/Engine/Source/Runtime/MeshDescription/Public/MeshDescriptionBase.h
Populates the passed array with adjacent polygons
void GetPolygonAdjacentPolygons ( [FPolygonID](API\Runtime\MeshDescription\FPolygonID) PolygonID, [TArray](API\Runtime\Core\Containers\TArray)< [FPolygonID](API\Runtime\MeshDescription\FPolygonID) > & OutPolygonIDs ) const